Power Factor Correction Converter Research Articles

Active-Clamp Resonant Power Factor Correction Converter With Output Ripple Suppression

An active-clamp resonant power factor correction converter with output ripple suppression is proposed and analyzed. It combines a buck power factor correction (PFC) unit and a resonant dc-dc unit by sharing one active switch. With another active-clamp switch, a recycling path is built to recover the leakage inductance energy of transformer, which improves the efficiency and the voltage stress of active switch. The effect of voltage ripple of dc link on output can be suppressed by fast voltage mode control loop. Therefore, low output current or voltage ripple can be achieved. With small voltage ripple across output of buck unit, the turn on time of active switch is almost constant in a half line cycle. Therefore, power factor correction can be achieved with inductor current of buck unit operating in discontinuous conduction mode (DCM). Finally, a 65W high power factor (PF) converter prototype for LED driver application with 91.08% peak efficiency and low output current ripple is built to verify the analytical results.

High-Efficiency Discontinuous Current-Mode Power Factor Correction-Based Plug-In Battery Charger for Local e-Transportation

This article presents a high-efficiency dual sensor-based two-stage battery charger for low-voltage battery packs. The charger utilizes a discontinuous current-mode (DCM)-based front-end ac-dc interleaved buck-boost converter for active power factor correction (PFC) and an unregulated LLC converter with synchronous rectification (SR) for achieving high efficiency. Only two sensors are utilized for implementing converter charge control, thus increasing converter reliability and robustness. A detailed loss analysis is done in order to estimate an optimal dc-link voltage for high performance along with small-signal modeling for closed-loop control. Experimental results from a proof-of-concept 1.0-kW hardware prototype are demonstrated in order to verify the converter feasibility. An input power factor of 0.99, an input current total harmonic distortion of 3.85%, and a high efficiency of 96.06% are achieved from the prototype.

Quasi-Resonant Bridgeless PFC Converter With Low Input Current THD

In this article, a quasi-resonant bridgeless power factor correction (PFC) converter is presented. Aiming to improve the input current total harmonic distortion, a single auxiliary switch with low voltage stress than the similar counterparts is employed. Due to resonant operation, the size and value of the passive components are reduced and maximum voltage gain of four is achieved which is higher than that of conventional buck PFC converter. Also, soft switching condition for the main semiconductor elements is realized from 20% of nominal power to full load and entire input voltage range (90 to 130 Vrms) without employing any extra component. The operating modes are explained and the theoretical analysis is discussed in details. A straightforward design procedure for the proposed converter is presented. A 200 W, 160 kHz laboratory prototype is implemented to verify the theoretical analysis and the effectiveness of the proposed topology.

Single-Phase LED Driver With Reduced Power Processing and Power Decoupling

Reduced power processing is a new trend to improve the conversion efficiency of light-emitting diode (LED) driver systems. Based on the concept, a new LED driver architecture is proposed in this article, which requires fewer power semiconductors compared with prior works, leading to the potential of lower cost and higher efficiency. A new ac/dc LED driver topology is derived accordingly based on the architecture to achieve the constant output current and unity power factor with significant energy storage reduction of the 100-/120-Hz energy buffer. Through a split and shared inductor, the required magnetic energy storage in the derived topology is the same as the conventional single-stage power factor correction converter, indicating high power density. Experimental evaluation verifies the performance in terms of improved power quality and conversion efficiency.

Pulse Train Control Strategy for CCM Boost PFC Converter With Improved Dynamic Response and Unity Power Factor

Pulse train (PT) control strategy for the boost power factor correction (PFC) converter operating in the continuous conduction mode (CCM) is proposed and studied in this article. Average current mode (ACM) control is usually utilized for the CCM boost PFC converter. The ACM-controlled PFC converter suffers from poor dynamic response, because its voltage control loop has to be designed with low bandwidth to minimize the effect of low-frequency output voltage ripple on the current control loop. Different from ACM control, the voltage control loop and current control loop of the PT-controlled PFC converter are decoupled, and thus the effect of low-frequency output voltage ripple on the current control loop is eliminated. Besides, PT modulation is utilized in the proposed controller to regulate the inductor current to follow the current reference. Thus, both high power factor and fast dynamic response can be achieved. The operation principle of the PT-controlled CCM boost PFC converter is analyzed, and a 300-W prototype is built to verify the analysis results. The experimental results show that power factor of the PT-controlled PFC converter is higher than 0.998 and the dynamic response is significantly improved.

Research on the Control Strategy of dual Boost bridgeless PFC based on Lyapunov stability

In order to prevent power electronic devices from causing harmonic pollution to the power grid, PFC technology is widely used between power electronic devices and the power grid. Therefore, the improvement of system power factor and robust performance has become a research focus today. This paper is aimed at dual Boost bridgeless PFC (power factor correction) converters, establishes a mathematical model in virtual dq mode, and a new nonlinear control strategy based on Lyapunov stability is proposed. The MATLAB simulation results show that the input current can better track the input voltage in the steady state, and when the load or output voltage changes, the system can quickly enter stability, and the system has strong anti-disturbance ability.

Mitigation of CM conducted EMI in flyback converter using balancing capacitors

The offline Switched Mode Power Supply (SMPS) draw non-sinusoidal line current from the utility power supply, thereby introducing unwanted harmonics and also generate significant electromagnetic interference (EMI). Power factor correction (PFC) converters can be used to improve the power factor. But they also generate EMI in both Differential Mode (DM) and Common Mode (CM). In this paper, the EMI generated by the flyback PFC converter is addressed. A lumped circuit model for CM conducted EMI generated in a flyback converter, including the HF transformer's parasitics and the components, is considered. The parasitics of the HF transformer are calculated and measured experimentally. Using them, the resonant frequencies of the flyback converter are calculated for validation. A technique for determining the required balancing capacitor to mitigate CM conducted EMI is presented. A novel technique by splitting this balancing capacitor with their mid-point grounded for further reduction of this EMI is presented. This technique can eliminate the C y capacitors of the EMI line filter connected between line/neutral to the ground. Hence for the same amount of CM conducted EMI mitigation, the size and the cost of EMI line filters are reduced. Theoretical analysis, simulation results, and experimental verifications are presented.

Port‐controlled Hamiltonian‐based controller for an interleaved boost PFC converter

This study reveals the energy shaping port-controlled Hamiltonian passivity-based control (PCH-PBC) technique for an interleaved boost power factor correction (IBPFC) converter. First, the mathematical modelling of an IBPFC converter is developed under all possible operating modes. Then, the average state-space model of the system is established with the help of averaging state-space technique. Further, the PCH technique is applied for controller design and the stability analysis of the proposed system is carried out. A proportional-integral (PI) controller is integrated with the PCH-PBC controller to achieve minimum steady-state errors. Finally, a Simulink model of the proposed system is developed using the Simulink toolbox of MATLAB software and its performances are studied under several operating conditions and verified through experimentation. To assess the system performance in terms of efficiency and input current total harmonic distortion (THD), the comparative study is also carried out under different controllers. Based on the simulation outcomes, the proposed controller is compared with the benchmark PI controller, adaptive passivity-based controller in terms of different control parameters. The performances of the controller are also investigated against dynamic variations at the input voltage and the load. It is observed that the proposed PCH-PBC controller achieves robustness against the aforesaid variations.

Experimental Verification of Single-Stage Power Factor Correction Converter with Improved Light-Load Efficiency

Single-stage single-switch ac/dc converters with power factor correction will have higher power losses under a light-load condition, as compared to that of two-stage approach, due to sharing of a common power transistor such that the power factor correction (PFC) stage cannot be switched OFF separately to save power losses. This paper addresses the problem by using a buck topology for the PFC stage of single-stage single-switch converters as it can completely turned OFF. This converter topology is capable of working in both buck mode and buck-boost mode depending on the rectified voltage at input side and power at load side. A simple and effective topology incorporating PFC for low power applications is simulated in Matlab/Simulink environment. Hardware implementation of the converter was and performance was verified with various practical light loads. It also satisfies the harmonic compliance of source current in accordance to the IEEE519:1992 recommendations. The control is very simple and gives good performance.

Dynamic AC Line Frequency Response Method for LUT-Based Variable On-Time Control in 360–800 Hz CRM Boost PFC Converter

To improve the input current total harmonic distortion (THD), the look-up table (LUT) method is used in the 360-800 Hz critical conduction mode (CRM) boost power factor correction (PFC) converter. When the ac line frequency changes drastically and suddenly, the zero-crossing detection method needs the half ac line period to follow the sudden frequency jump, causing a mismatching between the LUT and the ac line frequency. This mismatching in the time domain leads to a large current spike in the input current and even destruction in the PFC converter under some severe conditions. In this letter, a dynamic ac line frequency response method is proposed to eliminate this mismatching. The proposed method only needs to sample the input voltage, leading to a good performance in following the sudden frequency jump in a wide input voltage range. The effectiveness of the proposed method is verified with a 160 W GaN-based CRM boost PFC converter.

Non-visible transformations of chaotic attractors due to their ultra-low density in AC–DC power factor correction converters

Recently, it has been shown that DC–AC and AC–DC power converters whose dynamics is governed by two vastly different frequencies lead to a special class of piecewise smooth models characterized by a practically unpredictable number of switching manifolds between partitions in the state space associated with different dynamics. In the previous publications, we have shown that transformations of chaotic attractors in such models can be caused by their interactions with unstable cycles occurring in the regions of the attractors associated with an ultra-low invariant density, which is beyond a practical observability in physical or numerical experiments. The appearance of such low-density regions has been explained by the so-called spiking phenomenon. In the present paper, we make the next step and ask the natural question what are the reasons behind the appearance of spikes. Applying a novel technique (cobweb diagrams for non-autonomous maps), we explain a connection between spiking and the presence of two vastly different frequencies.

Characterization and Optimal Control of Totem-Pole PFC Converter With High Frequency GaN HEMTs and Low Frequency Si Diodes

A cost-effective totem-pole power factor correction converter with high-frequency gallium nitride high electron-mobility transistors and low-frequency Si diodes is investigated in this article. The reverse recovery characteristics of low-frequency diodes are evaluated experimentally. With the slow recovery characteristics, a negative current can flow through the low frequency diode, so that soft-switching and critical mode operation is achieved easily. However, if the duration of the negative current exceeds the reverse recovery time of the low-frequency diode, the diode will switch at high frequency, leading to severe losses and losing control of the inductor current. In order to avoid this issue, an adaptive off-time soft-switching strategy is adopted, and discontinuous conduction mode operation is suggested near the zero crossing of the grid voltage. Furthermore, since only the low-frequency grid current is sampled, this control strategy has the merits of low requirements on control resources and low cost. Experimental results of a 400W prototype are provided to verify the effectiveness of the proposed control strategy.

Average Periodic Delay-Based Frequency Adaptable Repetitive Control With a Fixed Sampling Rate and Memory of Single-Phase PFC Converters

This article proposes an average periodic delay-based repetitive controller for power factor correction (PFC) converters undergoing grid frequency variations. When the grid frequency is changed, a conventional repetitive controller requires an interpolation method or additional memory to achieve frequency adaptability. Furthermore, frequency adaptability can also be realized using a variable sampling frequency; however, this requires additional computation effort and a multirate digital control system. In this article, with a fixed sampling frequency and memory length, the proposed repetitive controller, which generates the average periodic delay unit, maintains its harmonic compensation performance under grid frequency variations. In the proposed method, the control variables are updated depending on the phase of the grid voltage to reflect the grid frequency deviations in the average period delay unit. Because no complicated software modification is necessary, the proposed scheme can be easily plugged in the existing control algorithm. The theoretical analysis and stability issues of the proposed scheme have been discussed in detail to ensure stable operation and disturbance rejection. Both the simulations and the experiments on a 1.5-kW PFC converter have been carried out to verify the effectiveness of the proposed repetitive control.

Battery Charger with Improved Power Quality Cuk Derived Power Factor Correction Converter

In this paper, a single switch single stage switched inductor based cuk converter with power factor correction control techniques is proposed. The main features of the proposed converter is low current stress, high voltage conversion ratio, reduction of components, high efficiency, low THD, etc., The operation of the proposed converter is explained in several modes along with the design of the converter. The performance of the proposed converter with different loads such as resistive, battery and motor loads with CC and CV control is analyzed and various factors such as power factor, efficiency and THD are compared. The Simulation work is carried out in MATLAB/Simulink software.

A Novel Bridgeless Cuk PFC Converter With Further Reduced Conduction Losses and Simple Circuit Structure

The bridgeless power factor correction (PFC) converter is popular for reducing the conduction losses of semiconductors. In this article, a novel bridgeless Cuk PFC converter is proposed. Compared with the conventional Cuk PFC converter, the number of conducting semiconductors in the proposed bridgeless Cuk PFC converter is reduced, contributing to lower conduction losses. Moreover, the conduction losses in the proposed converter are further improved compared with the pseudototem-pole bridgeless Cuk PFC converter. Meanwhile, the total number of the component in the proposed converter is less than other bridgeless Cuk PFC counterparts, especially for the big-volume magnetic component and electrolytic capacitor. In addition, all power switches in the proposed converter are common ground and can be driven by one control signal, availing simple drivers. The theoretical analysis of the proposed converter is presented in the discontinuous conduction mode with the merits of nature current-sharping ability, zero-current switching in semiconductors, and easy control. Finally, the simulation and a 100-W lab prototype are built to validate the feasibility of the proposed bridgeless Cuk PFC converter.

DC-Link and Switched Capacitor Control for Varying Coupling Conditions in Inductive Power Transfer System for Unmanned Aerial Vehicles

The use of wireless power transfer technology in unmanned aerial vehicle (UAV) systems is rapidly improving in different application areas. The main limitations of electric-powered UAVs are their charging range and stability in dynamic conditions. To solve these, this article proposes a hybrid control method based on dc-link and switched capacitor control with a fixed operating frequency. The dc-link voltage is regulated by the boost power factor correction converter to smoothen the output voltage, and the switched capacitor is used to dynamically compensate for self-inductance variations under dynamic coupling conditions. The output voltage stabilization and near-unity power factor of the input impedance can be achieved by applying the hybrid control method. Therefore, efficiency improvement can be achieved. Furthermore, the proposed control method can also be applied to systems with large coupling variations. To verify the proposed control method, a 500-W prototype was set up in the laboratory, and the experimental results proved that the control method could ensure a stable output voltage with horizontal and vertical offsets of 200 and 62 mm. respectively. Additionally, the results show that the maximum efficiency of the proposed control method is 91.9%, demonstrating that the proposed method effectively improves the efficiency.

Study of Power Quality Phenomenon Based on Design and Simulation of Boost Type PFC Converters

This paper present design and simulation of boost type Power Factor Correction (PFC) converter which improved the power quality. With the enormous development in the usage of power converters circuits like rectifiers which is non linear loads, the current drawn by these non- linear loads will not follow the supply voltage (i.e. non simulation). This results in high Total Harmonic Distortion (THD) and poor Power Factor (PF). Hence there is a need of converter topology to improve the PF and reduce line current harmonic. Boost type PFC converters is most popular topology for improving the PF in supply AC side. Average Current Mode (ACM) control technique is employed to control the boost converter in Continuous Conduction Mode (CCM). Simulation of proposed system is carried out using MATLAB/ Simulink platform.

On‐board electric vehicle battery charger with improved power quality and reduced switching stress

Development of charging infrastructure is one of the key factors for the successful operation of electric vehicles. This study proposes a power converter for on-board electric vehicle battery charger suitable with universal input voltage (85–265 V). The proposed converter is able to make better power quality by the reduction in total harmonic distortion (THD) of supply current, power factor correction and accurate output voltage regulation. System configuration includes diode bridge rectifier followed by three-level DC–DC SEPIC converter which emphasises on the reduction of voltage stress and switching loss across switches, thereby reduces the switch rating and improves the overall efficiency of the converter. The converter employs a duty cycle feed-forward controller scheme for charging the battery at constant voltage (CV) and constant current (CC) mode. Incorporating the above-said controller scheme has benefits of low THD in supply current, make power factor unity and nearly no zero-crossing detection. The proposed power factor correction converter system analysis is executed in continuous conduction mode. The system performance is evaluated with 400 V, 48 AH battery charging under CV and CC mode through MATLAB/Simulink and experimentation. To estimate the features of power quality indices like power factor and THD is recorded under the wide range of supply variations.

Maximum Efficiency Average Current Controller Based on a Comprehensive Charge Rate Model for DCM Boost PFC Converter

This article investigates modeling and control approaches to optimize the efficiency and power factor for discontinuous conduction mode boost power factor correction converters. First, with detailed consideration of parasitics and GaN HEMT transients, the input and output charges of the converter are exactly derived, where the rate forms the comprehensive charge rate (CCR) model. Second, based on the CCR model, the overall efficiency is derived. Since the overall efficiency is only related to the input voltage, output voltage, and switching on -time, an optimal on -time is calculated to achieve the maximum efficiency. Furthermore, with the optimal on -time, a maximum efficiency average current (MEAC) controller is proposed to regulate the input current while maintaining the maximum efficiency. With the predefined optimal on -time, a switching cycle modulation method is adopted to regulate the input current as sinusoid, which improves the power factor to unity. Finally, effectiveness of the MEAC control strategy is verified by simulations and experiments. Compared with conventional constant on -time control, it achieves an optimized efficiency and power factor over a large operation range.

Power quality improvements of arc welding power supplies by modified bridgeless SEPIC PFC converter

This paper proposes an efficient bridgeless power factor corrected (PFC) modified single ended primary inductor converter (SEPIC) for arc welding power supplies (AWPS). The overall configuration is composed of two converters: (1) a modified bridgeless SEPIC PFC converter, which is controlled by a PI controller to achieve a high power factor and fast response; and (2) a full bridge buck converter with high-frequency transformer for high-frequency isolation to ensure arc welding stability. The proposed system is simulated under different operating conditions of an AWPS. It is also tested in real time by a hardware-in-the-loop system based on a dSPACE DS1103 control board. The system performances are evaluated based on power quality indices such as power factor, total harmonic distortions of the AC grid current, and voltage regulation. The obtained results show that the proposed controller enhances the weld bead quality by keeping a constant current at the output and a stable arc, meet the international power quality standards and robustness for voltage regulation.